JP2011156732A - Inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus which can record a high-quality image quality by performing appropriate substitutional recording for an ejection defective nozzle without changing a recording order even in recording in which the recording order is regulated by limiting nozzles used for every ink color, and to provide a recording method thereof. <P>SOLUTION: When a non-ejection nozzle is detected by a detecting means for detecting non-ejection nozzles, recording data corresponding to the non-ejection nozzle in which an abnormality occurs is allotted to a nozzle where the ink recording order does not change by the presence or absence of substitutional recording. Substitutional recording is thus carried out. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and a recording method therefor, and more particularly, to a configuration for substituting another ejection port when there is a defective ejection port in a recording head.

  2. Description of the Related Art Conventionally, there is a known problem that the color to be recorded may differ depending on the ejection order of different colors of ink in an inkjet recording image or the difference in ejection time. The ink applied earlier tends to increase in density, and the density tends to change according to the time difference from the ink applied later. Due to these factors, inconveniences such as density difference and color tone difference occur in the sub-scanning direction, which is the feeding direction of the recording medium, and in the main scanning direction in which the recording head is scanned.

  As a method for solving this problem, there is known a method in which the ejection order and ejection time difference of different color inks are made constant by making the range or position of the nozzles used for recording different among the nozzle rows for each ink color. (See Patent Document 1).

  On the other hand, in a plurality of nozzles constituting the nozzle row as described above, clogging may occur, or nozzles that are not ejecting ink properly, such as non-ejection, may occur due to some cause. When such ejection failure occurs, ink dots that should be formed on the recording medium by the nozzles are not properly formed. As a result, streaks and density unevenness due to defective ink ejection occur in the recorded image, and the image quality may be significantly reduced.

  In response to such a problem, in a multi-pass method in which an image is completed by a plurality of scans (passes) of the recording head, the dots to be recorded by the defective ejection nozzles are changed to other normal by changing the mask used in a certain scan A method of performing alternative recording with a simple nozzle is known (see Patent Document 2).

JP 2002-307672-A JP 2006-168013 A

  However, in alternative recording with other nozzles described in Patent Document 2, when performing recording in which the nozzles to be used are limited in order to avoid image quality problems due to different recording orders as described in Patent Document 1, New challenges arise. That is, the ink recording order varies depending on the position of the nozzle for performing alternative recording, which may cause image quality degradation such as fine stripes and uneven density.

  In the present invention, even when the recording order is defined by limiting the nozzles to be used for each ink color, it is possible to perform alternative recording of appropriate ejection failure nozzles without changing the recording order, and to record high quality image quality. An ink jet recording apparatus and a recording method therefor are provided.

The present invention for solving the above problems is as follows.
According to a first aspect of the present invention, a plurality of recording chips or recording heads arranged in the main scanning direction for ejecting ink droplets of a plurality of colors according to recording data are scanned a plurality of times along the main scanning direction, and at least specified. An ink jet recording apparatus for forming an image on a recording medium so that the recording order is constant between the two types of inks, and a head capable of independently controlling the position and width of a nozzle for recording for each recording chip or recording head Control means and non-ejection detection means for detecting non-ejection nozzles of the recording head, and the recording order assigned to the non-ejection nozzles detected by the non-ejection detection means differs depending on whether or not alternative ejection is performed. An ink jet recording apparatus, characterized in that it is assigned to a nozzle that does not become a substitute and performs alternative ejection.

  In the second aspect of the present invention, the recording data assigned to the non-ejection nozzles detected by the non-ejection detection means is assigned to the nozzles in the used nozzle area defined for each recording chip or recording head to perform alternative ejection. The ink jet recording apparatus according to the first embodiment.

  According to a third aspect of the present invention, the recording data assigned to the non-ejection nozzles detected by the non-ejection detection means is added to the use nozzle area defined for each recording chip or recording head, and the non-ejection nozzles are added. Both the ink color of the assigned recording data and the ink color that should keep the recording order with respect to the ink color are assigned to the nozzles in the nozzle area where the use is not regulated, and the alternative ejection is performed. The ink jet recording apparatus according to the first embodiment.

  According to a fourth aspect of the present invention, the print order assigned to the non-ejection nozzles detected by the non-ejection detection means is different in the prescribed printing order in consideration of the presence or absence of other ink printing for each printing area. The inkjet recording apparatus according to the first embodiment, wherein allocation is performed within a range that does not occur, and alternative ejection is performed.

  In the present invention, in a recording apparatus that defines a nozzle area for recording for each ink in order to make the recording order unique, the recording data assigned to the nozzles determined as non-discharge nozzles by the non-discharge detection means is used as a substitute recording. Allocation is performed so that the recording order does not differ depending on the position of the nozzle to be performed, and alternative ejection is performed. For this reason, it is possible to reduce significant image quality degradation such as fine stripes due to the different recording order, and to maintain the high image quality obtained by making the recording order unique.

1 is a plan view showing an ink jet recording apparatus according to an embodiment of the present invention. It is a flowchart which shows the procedure of the undischarge complementation control using the unused nozzle performed in 1st and 2nd embodiment. It is a block diagram which shows schematic structure of the control system in this embodiment. FIG. 3 is a plan view illustrating an example of a recording head and a mask suitable for implementing the present invention in the first embodiment. FIG. 3 is a plan view schematically illustrating nozzles capable of alternative recording of non-ejection nozzles between a plurality of recording chips in the first embodiment. It is a top view which shows an example of the recording head and mask suitable for implementation of this invention in 2nd Embodiment. It is a top view which shows typically the nozzle which can perform the alternative recording of the non-ejection nozzle between several recording chips in 2nd Embodiment. It is a top view which shows typically the nozzle which can perform the alternative recording of the non-ejection nozzle between several recording chips in 3rd Embodiment. It is a flowchart which shows the procedure of the non-discharge complementation control using the unused nozzle performed in 3rd Embodiment. It is a top view which shows an example of the image data applicable in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view showing an ink jet recording apparatus (hereinafter also simply referred to as a recording apparatus) according to an embodiment of the present invention. The ink jet recording apparatus of this embodiment includes a main body 2 of a recording apparatus including a transport unit (not shown) that transports a recording medium in the Y direction (sub scanning direction intersecting with the main scanning direction). The main body 2 is provided with a carriage 1 attached so as to be movable along the guide shaft 33 in the main scanning direction. The carriage 1 is configured to be able to reciprocate by a driving force transmitted from a carriage motor (not shown) via a belt 34. A plurality of recording heads 5 for ejecting ink droplets are mounted on the carriage 1. The recording head 5 moves in the main scanning direction together with the carriage 1. In the recording head 5, a plurality of ejection openings (hereinafter also referred to as nozzles) are arranged for each ink of cyan (C), magenta (M), yellow (Y), black (Bk), and light gray (LGy). Nozzle rows are provided. The carriage 1 is mounted with ink tanks (not shown) that store the five types of ink. In the ink flow path of each nozzle provided in the recording head 5, there is provided an electrothermal converter for locally heating the ink to cause film boiling and ejecting the ink with the foaming energy. . Further, this ink jet recording apparatus is provided with a recording head recovery means in order to keep the ejection performance of each nozzle of the recording head 5 in an appropriate state. This recovery means covers the discharge port formed at the nozzle tip of the recording head 5 with a cap connected to a pump, and sucks and discharges thickened ink in the nozzle by the negative pressure generated in the cap by the pump. The so-called suction recovery mechanism 30 is configured.

  The carriage 1 is provided with an optical sensor 32. The optical sensor 32 detects the presence or absence of a recording medium on the platen 4 while moving in the main scanning direction together with the carriage 1. In addition, the ink jet recording apparatus of the present embodiment includes a non-ejection nozzle detection unit 36 having an irradiation unit and a light receiving unit that can detect non-ejection of ink for each nozzle. Specifically, optical detection is performed based on the presence or absence of ink droplets that block the optical path.

  In the ink jet recording apparatus configured as described above, the recording medium is transported in the sub-scanning direction from a transport unit (not shown). The recording head 5 receives a recording signal from a recording control unit (not shown), and ejects ink toward the recording area of the recording medium while moving in the main scanning direction together with the carriage 1. Recording is performed by repeating such a recording operation and a conveying operation for conveying the recording medium in the sub-scanning direction by a predetermined amount.

  FIG. 3 is a block diagram showing a schematic configuration of a control system in the present embodiment. The main control unit 300 includes a CPU 301 that executes processing operations such as calculation and control, a ROM 302 that stores a control program to be executed by the CPU 301, a RAM 303 that is used as a buffer for recording data, an input / output port 304, and the like. I have. The input / output port 304 is connected to drive circuits 305, 306, 307, and 308 such as a conveyance motor (LF motor) 312, a carriage motor (CR motor) 313, the recording head 5, and an actuator in the cutting unit. . Further, the input / output port 304 includes a head temperature sensor 314 that detects the temperature of the recording head, a home position sensor 310 that detects that the carriage 1 is at the home position where the recovery operation is performed, and the recording head 5. Detection devices such as an undischarge nozzle detection unit for inspecting the discharge state are connected. Further, the main control unit 300 is connected to the host computer 315 via the interface circuit 311.

  A control operation performed by the ink jet recording apparatus having the above configuration will be described.

(First embodiment)
FIGS. 4A to 4D are views for explaining nozzle rows and masks in the recording head according to the first embodiment of the present invention. For simplification of description and illustration, only two nozzle rows of black and light gray are shown, and a nozzle row of six nozzles is shown.

  In FIG. 4A, reference numeral 400 denotes two nozzle rows arranged in the main scanning direction corresponding to the discharge of two types of ink, black (Bk) and light gray (LGy), and the first nozzle row and the second nozzle row, respectively. Each column is composed of six nozzles from 0 seg to 5 seg.

  Reference numeral 408 denotes an example of a mask for Bk ink, and reference numeral 409 denotes an example of a mask for LGy ink. The ejection timing is determined by performing AND processing with print data to be recorded. The ON bit indicates a print-allowed pixel that allows ink ejection, and the OFF bit indicates a non-print-allowed pixel that does not allow ink discharge. Assuming that the vertical direction is the sub-scanning direction and the horizontal direction is the main scanning direction, the masks 408 and 409 are used corresponding to an area of 6 × 3 pixels (bits) on the recording medium. Using this mask, each of the Bk nozzle row and the LGy nozzle row completes an image in six scans. This will be described in detail next.

  For each scan of the recording head in the main scanning direction, the recording medium is conveyed by one nozzle pitch in the sub-scanning direction, which is the nozzle row direction, with respect to the recording head. At this time, since the mask is in a fixed position corresponding to the recording head, the mask also moves relative to the recording medium as the recording head moves relative to the recording medium. Using this example, a case where printing is performed on an area corresponding to one pixel in the vertical direction (sub-scanning direction) × three pixels in the horizontal direction (main scanning direction) as a recording area corresponding to one nozzle will be described as an example. To do. The rightmost pixel is recorded by 5seg of the Bk nozzle row in the first scan, the middle pixel is recorded by 4seg of the Bk nozzle row in the second scan, and the leftmost pixel is recorded by 3seg of the Bk nozzle row in the second scan. To be recorded. Next, the rightmost pixel is recorded by 2seg of the LGy nozzle row in the fourth scan, the middle pixel is recorded by 1seg of the LGy nozzle row in the fifth scan, and the leftmost pixel is recorded by 0seg of the LGy nozzle row in the sixth scan. Pixels are recorded. In this way, 100% printing of Bk ink and LGy ink is completed in a recording area corresponding to one nozzle in a total of six scans.

  As is apparent from the scanning order and the mask shape described above, by using this mask, the nozzles 401 to 403 are applied as the second area which is the nozzle use range (use area) of light gray (LGy) ink. To do. Then, ink is applied to the nozzles 404 to 406 as a first region that is a nozzle use range of black (Bk) ink. Thus, by setting the use range of the nozzle for each ink, the Bk ink is applied first in all the recording regions (all pixels thereof), and then the LGy ink is applied. At this time, in either case of unidirectional printing or bidirectional printing, the predetermined ink ejection order is Bk (black) → LGy (light gray), and the ink application order can be made constant.

  Note that the conveyance amount of the recording medium and the arrangement of the mask ON bits corresponding to each scan correspond to one nozzle pitch in order to simplify the explanation and illustration, and the above conveyance amount is equivalent to one nozzle pitch. Of course, it is not limited to. Similarly, the number of pixels in the main scanning direction for one nozzle on the recording medium has been described as three. However, the shape is not limited to this as long as ink is applied in the order of Bk → LGy.

  Next, an alternative recording of a defective ejection nozzle in the present embodiment will be described with reference to FIGS.

  In FIG. 4B, it is assumed that the nozzle 407 (406), which is 5 seg of the Bk nozzle row, is defective in ejection. Since ejection from this nozzle is not possible, all bit strings 416 corresponding to ejection failure nozzles 407 of the Bk mask are set to OFF bits. Then, in order to perform alternative printing with other ejectable nozzles, the OFF bit corresponding to the same position as the ON bit of the mask bit string 417 in any one of the other mask bit strings 411 to 415 is changed to the ON bit. By such a method, it is possible to perform alternative recording by ejecting ink to be ejected from the defective ejection nozzle 407 from other ejectable nozzles.

  However, depending on the position of the normal nozzle to which the recording data is allocated, the ink application order fixed in the order of Bk → LGy may be lost. For example, in the case of the ejection failure in FIG. 4B, if the recording data of the ejection failure nozzle 407 is assigned to any one of the mask bit strings (rasters) 411 to 413 corresponding to the nozzles of 0seg to 2seg, the Lgy ink is the Bk ink. Will be recorded earlier. Due to the difference in the ejection order, the streaks and density unevenness as described above occur.

  FIG. 4C shows an example applicable to this embodiment. A mask 420 and a mask 421 show two masks that can be used for alternative recording without different ink application order. The mask 420 is an example in which alternative recording is performed using a 4 seg nozzle, and the mask 421 is an example in which alternative recording is performed using a 3 seg nozzle. In either case, since the recording data is allocated to the nozzles included in the nozzle use range of the Bk ink, the ejection order of the Bk ink and the Lgy ink can be kept constant. Furthermore, as shown in FIG. 4D, by repeatedly using the mask 420 and the mask 421 in the main scanning direction on the recording medium, the recording order is kept constant without being concentratedly discharged from a specific nozzle. can do.

  FIG. 5 is a diagram for explaining alternative recording in a plurality of scans of the recording head in the case where the above-described ejection failure nozzle occurs. As the recording medium is transported, the recording head moves relative to the recording medium in the sub-scanning direction (paper discharge direction), and recording is performed in a unit area that can be recorded by one scanning of the recording head. It shows a state. This figure shows an example in which the recording head scans from the left side to the right side of the sheet to perform one-way recording.

  The recording data to be allocated to the ejection failure nozzle 506 in the Nth scan (pass) can be replaced by performing allocation printing in any of the (N + 1) to (N + 5) passes of the nozzles 501 to 505. That is, as described with reference to FIG. 4B, by changing the ON bit of the mask, the recording data of the defective ejection nozzle 407 is allocated to any of the other nozzles 501 to 505 to perform alternative ejection.

  However, as described above, if the recording data of the ejection failure nozzle 407 is allocated to the nozzles 501 to 503 of 0 seg to 2 seg, the use range of the nozzles for each ink that has been defined in advance so as to have a predetermined ink ejection order. Will be exceeded. As a result, the predetermined discharge order as described above cannot be achieved, and there is a possibility that image quality deterioration such as fine streaks due to a difference in color may occur. For this reason, it is desirable that nozzles within a predetermined nozzle use range, that is, nozzles 504 and 505 of 4 seg or 3 seg, be nozzles that perform alternative ejection of the defective ejection nozzle 506.

  Similarly, when ejection failure nozzles are generated in the nozzle row for recording LGy ink, the recording data is distributed among the 417 to 419 usage ranges of the LGy ink nozzles, that is, replaced with nozzles of 0 seg to 2 seg. Just record it.

  Here, the above-described control will be described with reference to FIG. First, in step S201, the nozzle non-ejection detection function unit 316 detects the ejection status of each nozzle. In step S202, the nozzle determined to be an ejection failure nozzle in step S201 is stored in the RAM 303 as undischarge information. Next, a recording method (recording mode) for recording is determined in step S203. That is, when there is a defective ejection nozzle such as non-ejection in any of the nozzles of the recording head, the multi-pass recording mode for performing the alternative recording described above is set. If there is no defective nozzle, a multi-pass printing mode is set in which the nozzle use range is limited without performing alternative printing. If the multi-pass recording mode is set, the process proceeds to step S206, where known multi-pass recording is started.

  When the recording mode for performing the alternative recording is set in step S203, in the next step S204, information on defective ejection nozzles is acquired from the RAM 303, and the defective ejection nozzles are specified. Based on this information, in step S205, the alternative recording of the defective nozzle is selected from the nozzles in the nozzle use range defined to make the recording order constant, and a mask is generated. . Using this mask, recording is performed in step S206.

  As described above, by selecting the nozzle for performing the alternative recording from the nozzle use range defined for each ink color or chip, the recording order of the ink does not differ even if the alternative recording is performed, and the image quality is improved. Deterioration can be reduced.

  In the present embodiment, in the limited mode, which is a recording mode in which recording is performed with a limited nozzle usage range, an alternative recording mode in which alternative recording is performed when there is a defective ejection nozzle, and a case where there is no defective ejection nozzle. The mode of selecting and executing from the multi-pass mode for performing multi-pass printing by limiting the nozzle use range has been described. The present invention is not limited to this. For example, a normal recording mode in which all nozzles are used, or a recording mode in which nozzles used for alternative recording can be selected from all nozzles when an ejection failure nozzle is detected. It may be selectable.

  Further, in the present embodiment, description has been made using an example of a print head in which the Bk ink nozzle row as the first nozzle row and the LGy ink nozzle row as the second nozzle row both have the same number of nozzles. The present invention is not limited. In other words, there is a possibility that the recording order is different when alternative recording is performed in the recording head in which the nozzle array of Bk ink and the nozzle array of LGy ink are arranged at least partially overlapping. The present invention can also be applied to such a recording head.

(Second Embodiment)
As a second embodiment, a mode in which nozzles not used for recording are provided in advance will be described. In FIG. 6A, reference numeral 600 denotes a two-row (black / light gray) ink nozzle array corresponding to the discharge of ink in the main scanning direction, and a recording head having six nozzles from 0 seg to 5 seg. Show. Reference numerals 608 and 609 denote masks used in this embodiment, which correspond to Bk and LGy, respectively. Similar to the first embodiment, the mask completes an image by six scans. Using such a mask, LGy ink is recorded by the second region of the nozzles 601 and 602, and Bk ink is recorded by the first region of the nozzles 605 and 606. At this time, the predetermined ink ejection order is set to Bk → LGy. Unlike the first embodiment, the raster corresponding to 2seg and 3seg does not have a portion where both Bk and LGy are ON bits. As a result, in the normal recording mode in which there is no defective ejection nozzle, 2seg and 3seg become the third region which is an unused nozzle.

  Next, a description will be given of alternative printing for defective ejection nozzles in the present embodiment. Here, it is assumed that 5seg and 607 (606) of the Bk nozzle row in FIG. In order to supplementally record the recording data to be recorded by this nozzle with other nozzles that can be normally ejected, a part of the mask is changed as in the first embodiment. That is, all 616 mask bit strings (raster) corresponding to 607 nozzles on the Bk mask are set to OFF bits. Then, by changing the OFF bit corresponding to the same position of the mask bit string in any one of the other mask bit strings 611 to 615 to the ON bit, the complementary recording can be performed by the nozzles that can normally eject. However, as in the above-described embodiment, depending on the position of the nozzle to which the recording data to be recorded by the defective ejection nozzle is allocated, an image defect occurs due to a different ink recording order.

  FIG. 7 is a diagram for explaining alternative recording in the present embodiment, and shows a state in which the recording head moves relative to the recording medium in the sub-scanning direction, as in FIG. The scanning direction of the recording head is rightward as shown in the figure, and unidirectional recording is performed.

  In the present embodiment, the recording data to be recorded in the N scan (pass) of the defective ejection nozzle 706 is supplied to the nozzles 703 to 705, and the recording data of the defective ejection nozzle 706 for performing alternate recording is used for other ink. This is because if the ink is allocated to the nozzles 701 and 702 that overlap with the use area, the ink application order of Bk → LGy is different. In this embodiment, since the unused area is provided in advance, it is not necessary to perform the replacement recording of the non-ejection nozzle only in the normal recording use area. That is, nozzles of 2 to 3 seg (703, 704) that are unused areas can also be used for alternative recording.

  FIG. 6C is a mask created based on the above conditions. In order to keep the ink ejection order, the recording data to be recorded by the ejection failure nozzles using any of the masks 617 to 619 is ejected to other ejections. Supply to a nozzle that is not defective. Further, as shown in FIG. 6D, by repeatedly using these masks in the main scanning direction according to the image data, it is possible to avoid the concentration of discharges at specific nozzles.

  Here, the above-described control will be described with reference to FIG. Steps S207 to S210 are the same as those in the first embodiment. In step S211, it is determined whether there is a region of the nozzle row in which neither the ink color to be subjected to alternative recording nor the ink color that should keep the ink ejection order for that ink color exists. If there is no nozzle area in which both ink colors are not used, in step S212, nozzles that are not defective ejection nozzles in the use area in which the ink color to be used for alternative recording is defined are the same as in the first embodiment. Select a nozzle to perform alternative recording. If there is an unused area in which both ink colors are not used, whether or not the prescribed ink recording order remains the same even if alternative recording is performed using the unused area in step S213. Determine. If the ink recording order does not change, a nozzle for performing alternative recording is selected from both the unused area and the area in which the ink color for performing alternative recording is defined in step S214. On the other hand, when the ink recording order specified when recording is performed in the unused area is lost, the unused area is not included in the options of the nozzle for performing the alternative recording, and the used area specified in step S212. Select a nozzle to perform alternative recording. In step S215, a nozzle is generated by selecting a nozzle that performs alternative printing according to the determinations in steps S211 and 212, and printing is performed in step S216.

  As described above, by selecting the nozzle for performing the alternative recording from the inside and the outside of the area defined for the ink color for performing the alternative recording, even if the alternative recording is performed, the image recording quality is not deteriorated without changing the ink recording order. Can be reduced. Further, the number of nozzles that perform alternative printing is increased as compared with the first embodiment, and an increase in load on a specific nozzle can be suppressed.

  In this embodiment, a case has been described in which the unused nozzle is a nozzle provided between two types of ink. Furthermore, according to the flow of FIG. 2B, it is also possible to perform alternative recording that keeps the ink recording order by using nozzles provided at other positions (the lowermost part of the head, the uppermost part, etc.).

  Further, in the present embodiment, an example has been shown in which when there is a defective ejection nozzle only in Bk ink, a nozzle for performing alternative recording can be selected from the Bk ink use area and the unused area. This is not a limitation. For example, when there is a defective ejection nozzle in both the Bk ink nozzle row and the LGy ink nozzle row, it is possible to select either one of the defective ejection nozzles to perform replacement recording from an unused area, thereby changing the recording order. Recording can be performed without making a difference.

(Third embodiment)
As described in the first and second embodiments, in order to make the order of ink application constant, the nozzles in the area overlapping with the other ink use areas cannot be used as the nozzles for the alternative recording. . However, it is only when other ink is actually used. In actual recording, not all inks are necessarily used for recording in all recording areas. Accordingly, depending on the recording area, there may be a nozzle area that does not perform recording. A method for performing alternative recording of ejection failure nozzles using a nozzle area where this recording is not performed will be described below as a third embodiment.

  FIG. 8 shows a recording head in which nozzle rows of two types of ink are arranged and each has six nozzles, as in the first embodiment. The main scanning direction of the recording head is rightward as shown in the figure, and unidirectional recording is performed. In order to make the recording order of ink constant, a use area is defined for each ink using a mask similar to that of the first embodiment. Reference numeral 801 denotes LGy ink, and 802 denotes a nozzle area used for recording Bk ink. That is, 0seg to 2seg are LGy and 3seg to 5seg are nozzles for recording Bk.

  An alternative recording of a defective ejection nozzle in this embodiment will be described. It is assumed that the Bk 5seg nozzle 805 is defective in ejection. In order to perform alternative recording, the recording data assigned to the nozzle 805 is allocated to the nozzle that performs alternative recording. As nozzles for substituting the N-th recording performed at 5 seg of Bk, which is an ejection failure nozzle, Bk nozzles (806 to 810) of 0 seg to 4 seg at (N + 1) to (N + 5) scans can be considered. As described in the first embodiment, when the alternative ejection is performed in the nozzle area for recording LGy, the ink ejection order is different. Therefore, it is necessary to perform the alternative recording in the nozzle area for performing Bk recording. However, when LGy is not recorded, the replacement recording may be performed at any position of 806 to 810, and the ink recording order is different between the area where the replacement recording was performed and the area recorded in the normal recording mode. This prevents image defects due to.

  FIG. 10 is an example of image data to which this embodiment can be applied. In the entire image data area 1001, 1002 is an area where only Bk is recorded, and 1003 is an area where Bk and LGy are recorded. When the area 1003 is recorded, the replacement recording of the Bk ejection failure nozzles as in the first embodiment must be performed by the nozzles in the area defined as the Bk nozzle. On the other hand, when the area 1002 is recorded, alternative recording can be performed without causing image defects such as streaks even in the area defined by LGy. Therefore, it is possible to change the selection width in the nozzle row for performing alternative recording based on the image data to be recorded.

  The control of this embodiment is demonstrated using FIG. In FIG. 9A, as in the first and second embodiments, the nozzle non-ejection detection function unit 316 detects the ejection status of each nozzle in step S901. In step S902, the nozzle determined to be an ejection failure nozzle in step S201 is stored in the RAM 303 as undischarge information. Next, in FIG. 9B, the recording mode for recording is determined in step S903. This recording mode is selected from either the normal recording mode or the alternative recording mode, as in the first embodiment. When the alternative recording mode is set, in step S904, information on defective ejection nozzles and recording data for pixels to be recorded by the nozzles are acquired from the RAM 303. In step S905, in a region where recording is performed, for example, a region where recording is to be performed by one scan of the recording head, ink that should comply with a predetermined ink recording order is recorded with respect to ink that needs alternative recording. Determine whether or not. In the case where ink is recorded to comply with a predetermined ink recording order, a mode is set in which nozzles to be complemented are selected from the nozzle areas defined for the ink to be subjected to alternative recording in the nozzle array of the recording head. If not, a mode for selecting a nozzle for performing alternative recording from the nozzle area defined for the ink for performing alternative recording and the nozzle area defined for the ink that is not recorded in the image area to be determined is selected. Set. In step S908, in accordance with the determination in step S905, a mask is generated so that the alternative recording of the defective nozzle can keep the predetermined ink recording order. In step S909, recording is performed using this mask.

  In this way, by changing the region for selecting the nozzles used for alternative recording according to the image data to be recorded, the number of nozzles that perform alternative recording increases while reducing image quality degradation due to different ink recording orders. An increase in the load on the nozzle can be suppressed. Furthermore, since it is not necessary to provide an unused area in advance, there is no reduction in throughput due to a decrease in the number of used nozzles. Of course, this embodiment can be applied even to the configuration of the second embodiment in which an unused area is provided.

(Other embodiments)
In the foregoing embodiment, two types of ink have been described, but the scope of application of the present invention is not limited to this. That is, it can be easily applied to a system defined for the ink recording order among three or more types of ink, and the essence of the invention is lost even if there is a third ink that does not need to keep the ink recording order. There is nothing. In addition, although the alternative recording of ink to be recorded first in the ink recording order has been described, it can be easily applied to alternative recording of ink to be recorded later.

  For simplicity, only unidirectional recording has been described. However, bidirectional recording can be easily applied by selecting a nozzle that performs alternative recording in consideration of the recording order that changes according to the recording direction. .

  In addition, the ink jet recording apparatus functions as the data processing apparatus of the present invention, and performs alternative recording processing of non-ejection nozzles in other scans. However, the application of the present invention is not limited to this configuration. is there.

  Furthermore, the present invention can also be realized by a program code that realizes the functions of the above-described embodiments and that realizes the procedure of the flowchart of FIG. 2 or a storage medium storing the program code. It can also be achieved by reading and executing the program code stored in the storage medium by the computer (or CPU or MPU) of the system or apparatus. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  The “recording medium” includes not only paper used in general recording apparatuses but also a wide range of cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. .

  Further, “ink” should be interpreted broadly as in the definition of “recording”. In other words, the “ink” used in the present embodiment is applied onto a recording medium, thereby forming an image, a pattern, a pattern, or the like, processing of the recording medium, or ink processing (for example, ink applied to the recording medium). A liquid that can be subjected to solidification or insolubilization of the colorant therein. The different types of inks may have different ink colors or may be liquids used for the above-described ink processing.

  Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port, a liquid path communicating with the ejection port, and an element that generates energy used for ink ejection.

  Further, the present invention shows a method of ejecting ink using an electrothermal conversion element, but a method of ejecting ink using an electromechanical conversion element such as piezo can also be adopted.

  In this embodiment, the width dimension of the recording medium is detected by using an optical sensor, and the detected data is input to the CPU as the control means. However, the width dimension of the recording medium is input by the user in advance. You may make it input into CPU via a means.

  In addition, the ink jet recording apparatus according to the present invention is provided as an image output terminal of an information processing device such as a computer as a single unit or as a separate unit, a copying apparatus combined with a reader, and a facsimile apparatus having a transmission / reception function. It may take a form.

  In the present invention, a software program for realizing the functional processing of the above-described embodiment is supplied directly or remotely to a system or apparatus, and the computer of the system or apparatus reads out and executes the supplied program code. Including the case of In this case, since the functions of the present invention are implemented by a computer, the program code itself installed in the computer also implements the present invention. The program installed in the computer may be any program that implements the functional processing of the present invention, and may be in any form such as an object code, a program executed by an interpreter, or script data supplied to the OS.

  Examples of the recording medium for supplying the program include a flexible disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, and magnetic tape. Other recording media for supplying the program include a nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R), and the like.

  In addition, the program can be supplied by connecting to the Internet using a browser of a client computer and downloading the program itself of the present invention or a compressed file including an automatic installation function from a homepage. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the scope of the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium, distributed to users, and the user who clears a predetermined condition is allowed to download key information to be decrypted from the homepage and encrypted with the key information. It is also possible to install by running the program.

  Further, the program read by the computer is executed to realize the functions of the above-described embodiment, and the OS or the like running on the computer performs part or all of the actual processing by the program, and the processing Also, the functions of the above-described embodiments can be realized.

  Further, after the program read from the recording medium is written to the function expansion board inserted into the computer or the memory of the connected function expansion unit, the CPU or the like performs part or all of the processing according to the program. However, the functions of the embodiments can be realized.

DESCRIPTION OF SYMBOLS 1 Carriage 2 Apparatus main body 4 Platen 5 Recording head 30 Recovery mechanism 31A Ink receiving box 31B Ink receiving box 32 Optical sensor 33 Guide shaft 34 Belt 35 Cutting unit 300 Main control part 301 CPU
302 ROM
303 RAM
315 Host computer 316 Undischarge nozzle detection unit

Claims (4)

A first nozzle row in which nozzles for discharging the first ink are arranged in the sub-scanning direction, and a nozzle for discharging a second ink different from the first ink are arranged in the sub-scanning direction. A recording head in which two nozzle rows are arranged along the main scanning direction intersecting the sub-scanning direction so that at least a part of the recording range by the first nozzle row and the recording range by the second nozzle row overlap in the same scanning. An inkjet recording apparatus that records an image in the unit region by scanning the unit region of the recording medium a plurality of times in the main scanning direction,
In the same scanning, an area recorded by the first area of the nozzles of the first nozzle array and an area recorded by the second area of the nozzles of the second nozzle array are in the sub-scanning direction. It is possible to execute a limited mode in which recording is performed using the first area and the second area that do not overlap,
Detecting means for detecting defective ejection nozzles in the first region and the second region;
When a defective discharge nozzle is detected in the first area by the detection means, image data to be recorded by the defective discharge nozzle is supplied to a nozzle that is not defective in discharge in the first area, and the detection means And a supply means for supplying image data to be recorded by the defective ejection nozzle to a nozzle that is not defective in ejection in the second area when a defective ejection nozzle is detected in the second area. Inkjet recording apparatus. The limited mode further includes a third region that discharges neither the first ink nor the second ink between the first region and the second region with respect to the sub-scanning direction,
When a discharge failure nozzle is detected in the first area by the detection means, the supply means outputs image data to be recorded by the discharge failure nozzle out of the nozzles in the first area and the third area. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is supplied to a nozzle that is not. The limited mode further includes a third region that discharges neither the first ink nor the second ink between the first region and the second region with respect to the sub-scanning direction,
If the detection unit detects a defective discharge nozzle in both the first region and the second region, the supply unit outputs image data to be recorded by the defective discharge nozzle in the first region to the nozzle in the third region. 2. The apparatus according to claim 1, further comprising: supplying image data to be recorded by the defective nozzles in the second area to nozzles that are not defective in ejection in the second area. 2. An ink jet recording apparatus according to 1. A judgment means for judging whether or not to record the first ink in the image data to be recorded in one scan;
When the detection unit detects a defective ejection nozzle in the second region and the determination result by the determination unit does not record the first ink in the image data to be recorded in the one scan, the supply unit 2. The ink jet recording apparatus according to claim 1, wherein image data to be recorded by the ejection failure nozzle is supplied to a nozzle that is not ejection failure in the first area and the second area.

Images